Sonic dental tool for massaging gums

ABSTRACT

A hollow elastic wand member forms a housing for an orbiting mass oscillator which comprises an eccentric rotor which is coupled by a flexible shaft to a drive motor. The rotor member is rotatably driven at a frequency such as to cause resonant elastic vibration of the wand in a gyratory vibration mode. This resonant frequency is chosen so that it is one at which energy can be efficiently coupled to gum tissue. Removably attached to one end of the wand member is an applicator member of soft resilient material which is utilized to couple the sonic energy to the gum tissue.

gs s, 33 9 40910 Lumsden United States Patent [54] SONIC DENTAL TOOL FORMASSAGING GUMS 8 Claims, 7 Drawing Figs. [52] US. Cl 128/36, l28/62,128/65 [51] lnt.Cl A61h1/00 [50] FieldofSear-ch l28/24.2,

[56] References Cited UNITED STATES PATENTS Primary Examiner-L. W. TrappAtmmey- Sokolski and Wohlgemuth ABSTRACT: A hollow elastic wand memberforms a housing for an orbiting mass oscillator which comprises aneccentric rotor which is coupled by a flexible shaft to a drive motor.The rotor member is rotatably driven at a frequency such as to causeresonant elastic vibration of the wand in a gyratory vibration mode.This resonant frequency is chosen so that it is one at which energy canbe efficiently coupled to gum tissue. Removably attached to one end ofthe wand member is an applicator member of soft resilient material whichis utilized to couple the sonic energy to the gum tissue.

SONIC DENTAL TOOL FOR MASSAGING GUMS This invention relates to a dentaltool and more particularly to such a tool involving the utilization ofsonic energy to massage gum tissue.

In furthering dental hygiene, it is highly desirable to regularlymassage the gum structure primarily to provide stimula tion to suchstructure and also to loosen and remove dirt between the gums and theteeth. To further these ends, certain vibratory dental instruments havebeen developed, including, for example, pulsing jets, and the electrictoothbrush. These devices, however, do not couple sonic energy to thegum tissue as efficiently as would be desired, this in view of severalfactors such as the lack of efficient impedance matching of thevibratory generator to the gums, and the failure ro provide optimumutilization of the available energy. In these prior art devices, theapplicator typically vibrates relative to the gums, and does not to anygreat degree transfer sonic energy to the gums such as to causevibration thereof.

The device of this invention provides a significant improvement overprior art gum massaging instruments by generating sonic energy in agyratory vibration mode in a resonant vibration system which includes anelastic stem or wand and the gum tissue itself. Such energy may befurther impedance matched to the gum tissue by means of a soft resilientapplicator which is coupled to the wand at an optimum impedance point inthe standing wave vibration pattern set up therealong. The use of aresonant elastic vibration system enables the optimum utilization of theavailable power in that the vibrational output can be developed in amost efficient manner.

It is therefore the principal object of this invention to facilitate andimprove the capability for massaging and cleaning gum tissue.

Other objects of this invention will become apparent as the descriptionproceeds in connection with the accompanying drawings, of which:

FIG. I is a perspective view of one embodiment of the device of theinvention;

FIG. 2 is a cross-sectional view taken along the plane indicated by 3-2in FIG. 1;

FIG. 3 is a cross-sectional view illustrating the applicator and rotormember ofthe embodiment of FIG. 1;

FIG. 4 is a cross-sectional view indicating an alternative form of rotormember which may be utilized in the device of the invention;

FIG. 5 is a cross-sectional view illustrating another alternative rotormember which may be utilized in the invention;

FIG. 6 is an elevational view illustrating an alternative applicatormember which may be utilized in the device of the invention; and

FIG. 7 is an elevational view illustrating another alternativeapplicator member which may be utilized.

It has been found most helpful in analyzing the device of this inventionto analogize the acoustically vibrating circuit utilized to anequivalent electrical circuit. This sort of approach to analysis is wellknown to those skilled in the art and is described, for example, inChapter 2 of Sonics by I-Iueter and Bolt, published in 1955 by JohnWiley and Sons. In making such an analogy, force F is equated withelectrical voltage E, velocity of vibration uis equated with electricalcurrent imechanical compliance C,, is equated with electricalcapacitance C,, mass M is equated with electrical inductance L,mechanical resistance (friction) R,, is equated with electricalresistance R and mechanical impedance 2,, is equated with electricalimpedance 2,.

Thus it can be shown that if a member is elastically vibrated by meansof an acoustical sinusoidal force F, sin mt(wbeing equal to 211 timesthe frequency of vibration), that i a... UL

Where wM is equal to I/wC,,,, a resonant condition exists, and theeffective mechanical impedance 2,, is equal to the mechanical resistanceRun the reactive impedance components wM and l/wC canceling each otherout. Under such a resonant condition, velocity of vibration uis at amaximum, power factor is unity, and energy is more efficiently deliveredto a load to which the resonant system may be coupled.

It is important to note the significance of the attainment of highacoustical Q" in the resonant system being driven, to increase theefiiciency of the vibration. thereof and to provide a maximum amount ofpower. As for an equivalent electrical circuit, the 0" of anacoustically vibrating circuit is defined as the sharpness of resonancethereof and is indicative of the ratio of the energy stored in eachvibration cycle to the energy used in each such cycle. Q ismathematically equated to the ratio between wM and R,,,. Thus, theeffective 0" of the vibrating circuit can be maximized to make forhighly efficient, high-amplitude vibration by minimizing the effect offriction in the circuit and/or maximizing the effect of mass in suchcircuit.

In considering the significance of the parameters described inconnection with equation (I), it should be kept in mind that the totaleffective resistance, mass, and compliance in the acoustically vibratingcircuit are represented in the equation and that these parameters may bedistributed throughout the system rather than being lumped in any onecomponent or portion thereof.

It is also to be noted that orbiting-mass oscillators are utilized inthe implementation of the invention that automatically adjust theiroutput frequency and phase to maintain resonance with changes in thecharacteristics of the load. Thus, in the face of changes in theeffective mass and compliance presented by the load with changes in theconditions of the work material as it is sonically excited, the systemautomatically is maintained in optimum resonant operation by virtue ofthe lock-in" characteristic of applicant's unique orbitingmassoscillators. Furthermore, in this connection, the orbitingmassoscillator automatically changes not only its frequency but its phaseangle and therefore its power factor with changesv in the resistiveimpedance load, to assure optimum efficiency of operation at all times.

Briefly described, the device of the invention comprises a hollowelastic wand member in which an eccentric rotor member is contained.Means are provided for rotatably driving the rotor member at a frequencysuch as to cause resonant elastic vibration of a vibration system whichincludes the wand member. Attached to the wand member at a low impedancepoint in the standing wave vibration pattern established therealong is aresilient applicator member for acoustically coupling sonic energy fromsaid wand member to gum tissue. The resonant frequency of vibration. ofthe vibration system including the wand member, the applicator memberand the gum tissue is chosen to be one at which gum tissue willnaturally respond in an efficient manner.

Referring now to FIGS. 1-3, one embodiment of the device of theinvention is illustrated. A hollow wand member 11 may be integrallyformed with a hollow handle member 12. Wand member 11 is fabricated ofan elastic material such as nylon. Contained within wand member 11 atone end thereof is an eccentric rotor member 14 which is coupled toelectric drive motor 15 by means of elastic shaft 16, guide bearing 17and drive shaft 18. Shafts I6 and 18 are fabricated of an elasticmaterial such as nylon, the guide bearing 17 acting to center the shaftswithin hollow wand member I1. Power may be provided for electric motor15 by means of battery 21, or if so desired, this motor may be of a typewhich is run off the AC power lines.

Removably attached to wand members 11 at one end thereof is flexibleapplicator member 23 which is made of a soft pliable material such asrubber. The applicator may be of a porous material such as foam rubberin which a cleaning solution could be impregnated. Applicator 23 has apick 24 formed therein which is applied to the gum tissue 27 and can fitbetween the teeth 28 as shown in FIGS. 1 and 2.

Motor 15 is operated at a speed such as to cause resonant elasticvibration of the resonant vibrating system including wand member 15.applicator member 23 and the gum tissue 27. This vibration frequency ispreferably a low frequency of the order of cycles per second so as toprovide optimum energy transfer to the gum tissue. The vibrationalpattern generated by rotor 14 is circular or gyratory in mode, thusproviding the application of both compressional and shear stress on thegum tissue for optimum impedance match by applicator member 23. It is tobe noted that in view of the circular vibrational pattern of the energyprovided to the applicator, its orientation relative to the gums andteeth is not critical. It is further to be noted that applicator member23 is attached to elastic wand member ll at the end thereof, which is apoint of low impedance in the standing wave vibration pattern, i.e.,near a velocity antinoble. This assures good impedance matching to thegum tissue through the resilient applicator 23.

Referring now to P16. 4, an alternative form of eccentric rotor whichmay be utilized in the device ofthe invention is illustrated. Thisrotor, rather than having the semicircular form of the rotor FIG. 3,rather has an cccentrically located hollowed out portion M-aformedtherein, the outside walls of the rotor having a diameter just slightlyless than the inside diameter of wand member 13. It thus can be seenthat in view of the mass unbalance of this rotor that the'desiredgyratory vibration of wand member 11 will be induced.

Referring now to FIG. 5, another embodiment of rotor 14 is illustrated.This particular embodiment involves a relatively small diametercylindrical element which is driven by rolling around within the racewayformed by the inner walls llaof wand member 12. This particular type ofrotor has the ad vantage in that it provides a frequency stepdown in thevibration frequency from the rotation frequency of shaft 16, and isuseful in obtaining the desired low frequency vibrational output inconjunction with a somewhat higher speed motor.

Applicator member 23 preferably is made so that it is readiiy detachablefrom wand member 11 so that it can readily be replaced for applicatormembers exchanged for use by different persons. Applicator member 23thus is preferably made so that it can be stretched to fit over the endof the wand in a hold tight relationship therewith. The end of wandmember 11 is preferably roughened to provide friction to aid in holdingthe applicator member thereto.

Referring now to PK]. 6, another type of applicator member which may beutilized with the device of the invention is illustrated. Thisapplicator, as for the applicator just described is of a flexible softmaterial which can be stretched to fit the end of wand member ll.However, rather than having a single pick member, it includes aplurality of pointed pick sections 3% for working between the teeth.

Referring now to H6. '7, still another applicator member which may beutilized in the device of the invention is illustrated. This applicatormember is also of flexible soft material which can be stretched on theend of wand member 11, and includes a plurality of concentric ridgessections 32 as the working elements.

The device of the invention thus provides a highly efficient gummassaging instrument which utilizes resonant sonic energy coupled to thegum tissue to implement the massaging action.

Iclaim:

1. A dental tool for massaging and cleaning gum tissue comprising:

a hollow wand member fabricated of elastic material;

an applicator member removably attached to one end of said wand member,said applicator member being fabricated of a soft resilient material;

a handle member attached to the other end of said wand member;

an eccentric rotor member rotatably supported in said wand member; and

motor means for driving said rotor member at a speed such as to causeresonant elastic gyratory vibration of the vibration system includingsaid wand member, said appllicator member and said gum tissue. 2. hetool of claim 1 wherein said handle member lS hollow, said motor meansincluding an electric motor mounted in said handle member.

3. The tool of claim 1 wherein said resonant vibration is at a frequencyof the order of 20 cycles-per second.

4. The tool of claim 1 wherein said rotor member comprises a cylinderhaving a substantially smaller outside diameter than the inside diameterof said wand member, said cylinder rolling around against the inner wallof said wand member to provide a vibration of said wand member at afrequency substantially lower than the rotation frequency at which saidrotor is driven.

5. The device of claim 1 wherein said applicator member is fabricated ofa porous material capable of holding cleaning solution.

6. The device of claim 1 wherein said rotor member comprises a cylinderhaving substantially the same outside diameter as the inside of saidwand member, said cylinder having an eccentric hollowed out portionformed therein.

7. The device of claim 1 wherein said applicator member is cylindricalin form and has a plurality of pointed applicator units formedtherearound.

8. The device of claim 1 wherein said applicator member is cylindricalin form and has a plurality of concentric circular ridge portions formedthereon.

1. A dental tool for massaging and cleaning gum tissue comprising: ahollow wand member fabricated of elastic material; an applicator memberremovably attached to one end of said wand member, said applicatormember being fabricated of a soft resilient material; a handle memberattached to the other end of said wand member; an eccentric rotor memberrotatably supported in said wand member; and motor means for drivingsaid rotor member at a speed such as to cause resonant elastic gyratoryvibration of the vibration system including said wand member, saidapplicator member and said gum tissue.
 2. The tool of claim 1 whereinsaid handle member is hollow, said motor means including an electricmotor mounted in said handle member.
 3. The tool of claim 1 wherein saidresonant vibration is at a frequency of the order of 20 cycles persecond.
 4. The tool of claim 1 wherein said rotor member comprises acylinder having a substantially smaller outside diameter than the insidediameter of said wand member, said cylinder rolling around against theinner wall of said wand member to provide a vibration of said wandmember at a frequency substantially lower than the rotation frequency atwhich said rotor is driven.
 5. The device of claim 1 wherein saidapplicator member is fabricated of a porous material capable of holdingcleaning solution.
 6. The device of claim 1 wherein said rotor membercomprises a cylinder having substantially the same outside diameter asthe inside of said wand member, said cylinder having an eccentrichollowed out portion formed therein.
 7. The device of claim 1 whereinsaid applicator member is cylindrical in form and has a plurality ofpointed applicator units formed therearound.
 8. The device of claim 1wherein said applicator member is cylindrical in form and has aplurality of concentric circular ridge portions formed thereon.